Solution spinning process for the production of a textile fiber material with a permanent repellent action

ABSTRACT

A solution spinning process for the production of a textile fiber with permanent repellent action includes the steps of preparing a spinnable polymer component and an ambivalent polymer compound which contains a repelling group and a residual group with an affinity for the spinnable polymer component, mixing the ambivalent polymer compound with the spinnable polymer component in a solvent, and spinning the mixture into a fiber, wherein the repelling groups orient themselves in the direction of the surface of the forming fiber and migrate to the surface, while the affine residual groups anchor the ambivalent polymer compound in the spinnable polymer compound as the solvent is driven off.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of Internationalapplication PCT/EP02/00318 filed Jan. 15, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process for the production of atextile fiber which has a permanent repellent action.

2. Description of the Related Art

Textile materials with repellent properties especially for the repulsionof oil, water, and dirt are known in the state of the art. Thus, EP 0377 813 describes a canopy top material for motor vehicles, where, toachieve the desired repellent properties, the surface fabric is finishedwith a repellent agent, specifically in this case with a polymer basedon fluoropolymers. Fluorine waxes for clothing textiles are also known;these can be in the form of impregnating sprays, which are sprayed ontothe surface of the fibers. The disadvantage, however, is that theserepellents wear off over the course of time, because they are not boundpermanently to the surface of the fiber.

Known fluorocarbon systems with improved repellent properties areprovided with resin groups (melamine resins, polyisocyanates), which cancrosslink with themselves. This has the result that, after the fibershave been coated with these fluorocarbons, the fibers are enclosed by anetwork formed by the resin groups (see FIG. 3). The fluorocarbon groupsproject out from this network and exert their repelling effect withrespect to, for example, water or dirt. These types of fluorocarbons areused, for example, for automobile canopy top material and have beenfound to give good results. The disadvantage is that the repellingeffect described above is reduced or completely lost during the use ofthe canopy top material, in that the fluorocarbons are worn away by, forexample, the wind caused by driving, by the friction created by dust, byrepeated folding, and by other environmental effects as well. Thenetwork enclosing the fibers can be torn apart by the effects justmentioned. Thus it is even possible for large areas of the repellentsystem to separate from the fiber product. This leads to an increase inthe amount of dirt which can adhere to the fibers and thus gives thecanopy top material an unattractive appearance. This-problem iscurrently being dealt with by using only dark-colored canopy topmaterials. It is precisely in this area of application, however, thatthere is a desire to use colored fiber products which coordinate withthe color of the motor vehicle.

U.S. Pat. No. 6,063,474, furthermore, describes a thermoplastic fiber,especially a polyolefin fiber, the production of which includes theintroduction of fluorocarbon esters into the polyolefin melt before itis extruded into fiber. If their nature allows, these incorporatedfluorocarbon esters can become concentrated at the surface, where theycan exert their repelling effect. Because neither the fluorocarbon groupnor the hydrocarbon group belonging to the ester forms a bond with thethermoplastic fiber, the repellent is therefore held by purelymechanical means in the fiber mass in this case also. A permanentrepelling effect can therefore not be expected.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a production processfor a textile fiber with which a permanent repelling action is achieved.

This object is accomplished by a process for the production of a textilefiber preparing a spinnable polymer component and an ambivalent polymercompound which contains a repelling group and a residual group with anaffinity for the spinnable polymer component, mixing the ambivalentpolymer compound with the spinnable polymer component in a solvent, andspinning the mixture into a fiber, wherein the repelling groups orientthemselves in the direction of the surface of the forming fiber andmigrate to the surface, while the affine residual groups anchor theambivalent polymer compound in the spinnable polymer compound as thesolvent is driven off.

The essential feature of the textile fiber produced according to theinvention is the ambivalent polymer compound, which is composed of twodifferent groups, namely, the repelling group and a residual group,which has an affinity for the fiber matrix.

In contrast to the known substantive systems described above, which arepresent on the surface of the fiber, the repelling group in this case isbonded to the fiber polymer by way of the affine residual group. It istherefore virtually impossible for the repellent group to be rubbed off,because it would by necessary for the affine residual group to be tornout of the fiber polymer structure at the same time. Additionaladvantages and features can be derived from the subclaims.

Fluorocarbon groups are preferred as the repellent groups, but siliconepolymers could also be used.

The affine residual groups are groups which have a definite affinity forthe fiber polymer. If, for example, a polyacrylonitrile fiber is to beproduced, ambivalent polymer compounds with nitrile groups as the affineresidual groups are preferred. When other fiber polymers are used(polyamides, polyacrylates, etc.), the affine residual groups for theambivalent polymer compound would be selected in correspondence with thechemical structure of the fiber polymer.

A composition consisting of a spinnable polymer component and anambivalent polymer compound, where the affine residual group of theambivalent polymer compound has an affinity for the spinnable polymercomponent, can be used to produce textile fiber material such asmonofilaments, multifilaments, fibers, yarns, or flat materials.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of the disclosure. For a better understanding of the invention, itsoperating advantages, specific objects attained by its use, referenceshould be had to the drawing and descriptive matter in which there areillustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIGS. 1 a-1 c show various stages of the production process for atextile fiber according to the invention;

FIG. 2 shows a cross section of a textile fiber according to theinvention; and

FIG. 3 shows a cross section of a textile fiber according to the stateof the art.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a shows a composition according to the invention. The twoessential components provided for the production of a textile fiber witha permanent repelling action, namely, the spinnable polymer component 1and the ambivalent polymer compounds 2, are mixed together. Theambivalent polymer compound 2 has two different groups. The first is thefluorine-containing polymer chain as the repellent group 2.1, such aspolytetrafluoroethylene. The ambivalent polymer compound 2 also has, atthe other end, an affine residual group 2.2. This affine residual group2.2 has the ability to interact with the fiber polymer 1. In FIG. 1 a,polyacrylonitrile is used as the fiber polymer 1, and a hydrocarbon withnitrile groups is used as the affine residual group 2.2. In the presentexample, the two polymer components 1 and 2 are dissolved in a solvent3, especially a polyalcohol such as polyether glycol. The amount of thetwo polymer components 1 and 2 in the solvent is approximately 20-30 wt.%. After components 1 and 2 have been mixed together, the mixture isspun, during which the solvent is driven off. The repellent groups 2.1,which are repelled by the fiber polymer 1, start to orient themselvesimmediately in the direction of the arrows 4, that is, in the directionof the fiber surface (FIG. 1 b). The residual groups 2.2 slow down thisprocess as a result of their affinity for the fiber polymer 1. In FIG. 1c, the spun fiber can be seen. The repelling groups 2.1 project out fromthe surface 5 of the fiber 6. Between the fiber polymer 1, i.e., thepolyacrylonitrile, and the nitrile groups of the affine residual group2.2 there are van der Waals interactions, as a result of which theambivalent polymer compound 2 is held in the fiber structure. Dependingon the amount of polymer compound 2 in the fiber 6, 10-15 wt. % beingpreferred, it is also possible, of course, for polymer compound 2 alsoto be present within the fiber, as indicated in FIG. 2. These cannotarrive at the surface 5 until a space has become free at the surface 5.

Even if it is not completely clear from the figures, the fiber 6 haspolymer groups 2.2 with repellent properties all the way around itscircumference, that is, over its entire surface 5.

When we now compare this fiber according to the invention in FIG. 2 withthe state of the art, shown in FIG. 3, the essential difference isobvious. Fluorocarbons 7.1 also project from the surface 5 of the knownrepelling fiber 1 and exert the repelling effect. At the terminal,however, there are no groups which are held in the fiber mass; instead,there is only a resin component 7.2, which reacts with itself and formsa network 8 enclosing the fiber 6. As a result of external influences,it is possible for the polymer compound 7 with its repelling group 7.1to be torn out of the network, and it is even possible for whole areasof the network to be torn from the fiber. The fiber is then susceptibleto attack by dirt in these areas.

In the case of the fiber 6 according to the invention (FIG. 2), this isnot possible or at least not possible to anywhere near the same extent,because the ambivalent polymer compound 2 is bonded to the fiber mass byway of the groups 2.2.

The compositions of polymer component and ambivalent polymer compound 2used for the production of the textile fibers can contain otheradditives as appropriate for the area of application of the fibers. Inthe case of clothing textiles and material for the motor vehicleindustry, furthermore, colored fibers are desired. In these cases, colorpigments will be added to the compositions according to the invention.For other applications, admixtures of stabilizers, quenchers, slipagents, or ceramic or metallic reinforcing fibers are also conceivable.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

1-6. (canceled)
 7. A solution spinning process for the production of atextile fiber with permanent repellent action, the process comprisingthe steps of: preparing a spinnable polymer component and an ambivalentpolymer compound which contains a repelling group and a residual groupwith an affinity for the spinnable polymer component, mixing theambivalent polymer compound with the spinnable polymer component in asolvent, and spinning the mixture into a fiber, wherein the repellinggroups orient themselves in the direction of the surface of the formingfiber and migrate to the surface, while the affine residual groupsanchor the ambivalent polymer compound in the spinnable polymer compoundas the solvent is driven off, further comprising using the textile fiberfor clothing textiles or industrial textiles.
 8. The process accordingto claim 7, wherein the textiles are used for the motor vehicleindustry.